Tool support structure



Aug. 19, 1969 J. H. HERZOG ETAI- TOOL SUPPORT STRUCTURE Filed Feb. 20,1967 a may NZ/ Ek n v: N 6 4 0 3 M ATTORNEYS United States Patent AOffice 3,461,763 Patented Aug. 19, 1969 3,461,763 TOOL SUPPORT STRUCTUREJohn H. Herzog, Clarence, and Ronald C. Hill, Corfu, N.Y., assignors toHoudaille Industries, Inc., Buffalo,

N.Y., a corporation of Michigan Filed Feb. 20, 1967, Ser. No. 617,104

Int. Cl. B26d 7/06 US. Cl. 83-436 11 Claims ABSTRACT OF THE DISCLOSURE Apunch press is provided with a releasable guide assembly in the form ofa yoke adjacent to its ram, within which there are reciprocablestripping means that slidably guide a toolholder normally supported bythe ram. On detachment of the guide assembly from the press whichreleases the toolholder from the ram, a pair of pivotable leversautomatically move into a position where they jointly temporarilysupport the toolholder while a punch tip portion is replaced. Release ofthe levers is automatic in response to resecuring the guide assembly.

Background of the invention Field of the inventin.This inventionpertains to structure for automatically supporting a toolholder when thesame is temporarily disconnected from a supporting ram during a toolchange.

Description of the prior art.In Patent No. 3,270,605 owned by theassignee of this invention there is shown a guide assembly, and there isalso shown structure for fixedly securing the guide assembly to astationary portion of the press. On release of the clamping mechanismstherein disclosed and claimed, the toolholder or guide assembly can bemoved out of its normal operating position to enable manual access tothe tooling carried therein for the purpose of effecting a tool change.In that device, the punching structure is supported by the guideassembly, and the ram has nothing supported by it. This arrangement isentirely satisfactory for punch elements up to a certain size, assufficient stripping energy can be stored conveniently in springs.However, where the maximum tool size has been increased considerably, adifferent stripping arrangement has been necessitated which entailed aT-slot arrangement by which the punch element was indirectly supportedby the ram. When such an arrangement has been combined with thereleasable guide assembly of the type shown in Patent No. 3,270,605, aproblem has arisen as to how to support the tooling when the guideassembly has been detached from the ram, such problem being heightenedby the fact that the tooling is of considerable weight, and is subjectto damage in the event that it is inadvertently dropped.

Summary In accordance with the present invention, we have provided inthe disclosed embodiment a pair of pivotable levers which are normallypivoted to a retracted position because of the influence of an abutmenton the press, and which automatically pivot to a position where theyjointly support the toolholder whenever the guide assembly is moved outof its normal supported position, such movement simultaneouslydisconnecting the toolholder from the ram. On restoration of thetoolholder and the guide assembly to their operating position where theyare again secured, the supporting means automatically release thetoolholder, freeing it for reciprocation in response to the movement ofthe ram.

Accordingly, it is an object of the present invention to provide toolsupport structure which automatically supports tooling at such time asthe tooling is released from its normal support.

Another object of the present invention is to provide supporting meansfor tooling which means are responsive to the release and the securementof the structure that supports the tooling so as to have a temporarilyopposite effect.

A further object of the present invention is to provide a safetymechanism to preclude inadvertent release of the temporary supportingmeans.

Many other advantages, features and additional objects of the presentinvention will become a manifest to those versed in the art upon makingreference to the detailed description and to the accompanying sheet ofdrawings in which a preferred structural embodiment incorporating theprinciples of the present invention is shown by way of illustrativeexample.

On the drawings:

FIG. 1 is a side cross-sectional view of tool support structure providedin accordance with the principles of the present invention; and

FIG. 2 is an enlarged fragmentary top plan view of a portion of FIG. 1,FIG. 1 being taken generally along the line I--I of FIG. 2.

As shown on the drawings:

The principles of this invention are particularly useful when embodiedin a tool support structure such as illustrated in FIG. 1, generallyindicated by the numeral 10. The tool support structure 10 is providedfor use with a press, such as a punch press having a reciprocable ram 11and a portion 12 which for purposes of this invention comprises anabutment. The press includes conventional stationary portions (notshown) adjacent to the ram, of the type described in the above-mentionedpatent to which a guide assembly 13 is releasably secured, such as bymeans shown in said patent. The left side of FIG. 1 represents the frontof the machine which would be facing toward the operator, and inaccordance with such prior patent, the guide assembly 13 has an armextending toward the viewer that has been removed because of sectioning,and a rearwardly extending arm obscured by the illustrated structurewhich jointly comprise a yoke of a known type. When such yoke or guideassembly 13 is released, the guide assembly 13 is free to be movedhorizontally to the left away from the abutment 12, and away from theram 11, out of all engagement therewith. To restore the press tooperating condition, the guide assembly is moved to the right to theposition drawn where the same is secured in operating position by theknown clamping means identified above.

The guide assembly 13 includes a bushing 14 which is held in a fixedposition in a conventional manner, and which defines a first aperture15. The aperture 15 receives and slidably guides the lower portion ofstripping means 16 for reciprocation, the stripping means 16 having asuitable keying means 17 to preclude rotation between such strippingmeans and the bushing 14. The stripping means 16 has a second aperture18 which is concentric with the first aperture 15. The second apertureslidably receives a toolholder 19. Suitable keying 20 is providedbetween the toolholder 19 and the stripping means 16 to precluderelative angular rotation. The upper end of the toolholder 19 isconnected to the ram 11 by means of a T-slot and T-head connection, inthis embodiment, the T-head 21 being a part of the toolholder 19, andthe T-slot being a part of the ram 11 and extending in a front to reardirection. The toolholder 19 has a continuous circumferential groove 22which defines and provides a downwardly directed shoulder 23 lying in ahorizontal plane and being convex as viewed from the side.

The stripping means 16 includes a stripping sleeve 24 which carries thekeying 17 and which has an internal keyway for the keying 20. At itslower end, the stripping sleeve 16 supports a stripping plate 25 as by asnap ring 26, the stripping plate being here illustrated with a maximumdiameter to coact with a maximum diameter punch tip 27 supported by thetoolholder 19. The stripping sleeve 24 has a flange 28 at its upper endwhich is trapped by a snap ring 29 in a downwardly facing recessprovided in a stripping collar 30. The stripping collar is generallycircular, but has a forward ear 31 and a rearward ear 32. A set of fourlifter springs 33 acts between the guide assembly 13 and the strippingcollar 30, while a set of four lifter spring bolts 34 acts between thestripping collar and the guide assembly 13 to place a preload on thelifter springs 33 of such magnitude as to insure that the strippingcollar 30 will take a normal rest position as illustrated.

As a matter of interest, and not forming a part of this invention, theabutment 12 acts on the rear ear 32, and a similar component 35 actsthrough an ear extension 36 on the forward ear 31 of the strippingcollar 30 to hold the stripping plate 25 in firm engagement With theworkpiece during punching and stripping. The structure described enablesthe bushing 14, the stripping sleeve 16, the toolholder 19, andincluding the head 21 and the punch tip 27 to be rotated to any selectedangular position so that where the punch tip 27 is non-circular, itsShape may be oriented properly in an angular manner with respect to theworkpiece.

Considering only the structure thus far described, if the guide assembly13 were shifted to the left, such that the toolholder head 21 coulddisengage from the ram 11, the toolholder 19 and the punch tip 27 wouldfall through and drop out at the bottom of the guide assembly 13. Such aproperty is necessary to enable the ram 11 to reciprocate the toolholder19 with its tool bit 27.

In accordance with another of our inventions, the toolholder 19 has amanual actuator 37 which is rendered accessible to the operator when thetoolholder 19 has been moved to the left out of engagement with the ram11. To understand the present invention, it is sufiicient to explainthat manual movement of the manual actuator 37 will release the punchtip 27 from the toolholder 19, so as to permit it to drop, such as intothe palm of the operator. Such condition enables the operator to replacethe punch bit 27 with a further selected punch tip. Normally, theoperator will also replace the stripping plate 25 by removal of the snapring 26 which has ears (not shown) facilitating such replacement.

In accordance with the present invention, supporting means generallyindicated at 38 are provided, which can best be seen in FIG. 2. Thesupporting means 38 includes at least one and preferably two pivotablelevers 39, 40, respectively secured pivotably as by a pair of screws 41,42 which extend into the stripping collar 30 of the stripping means 16.The lever is substantially a mirror image of the lever 39, and thelevers 39, 40 are disposed on the opposite sides of, namely to the leftof and to the right of the axis of the apertures 15, 18 as viewed by theoperator, Each of the levers 39, 40 has a concave knifelike portion 43and a concave cam surface 44. A spring 45 connects the levers 39, 40 forbiasing the knife-like portions 43 toward each other and hence towardthe groove 22 with which they are aligned. As the guide assembly 13 iswithdrawn to the left, all of the structure illustrated in FIG. 2 movesto the left except for the abutment 12. As such movement begins, theends 46 of the cam surfaces 44 are cammed apart aided by the spring 45to enable the knife edges 43 to move into the groove 22 where the uppersurface of the knife edges 43 may engage the downwardly directedshoulder 23 before the toolholder head 21 is fully disengaged from theram 11. In this first position the lever or levers 39, 40 temporarilyretain the toolholder 19 against dropping out to enable the operator tomake a selected change in choice of punch bit 27. On completion of suchchange, return of the structure shown in FIG. 2 toward the abutment 12causes the abutment 12 to be engaged by a pair of ears 47 which form theinner end of the cam surfaces 44 whereby the levers 39, 40 are graduallydrawn to the position shown in FIG. 2 wherein the ear portions 47 actagainst the abutment 12 against the force of the spring 45 to hold thelevers 39, 40 in the second or retracted position wherein they arespaced from the toolholder 19. The illustrated position is thus thenormal operating position wherein the cam surface 44 is engaged by theconvex portion of the abutment 12 on the press.

Considering the supporting means 38 thus far described, when the guideassembly 13 has been shifted to the left and the supporting means 38 areholding the toolholder 19, it is possible due to an inadvertence, suchas carelessness, to manually grasp the rearwardly directed cars 46, 46and to move them together, thereby effecting release of the toolholder19 which would then dro through the guide assembly 13. The location ofthe supporting means 38 at the rearward part of the stripping means 16is intended to render the supporting means 38 less accessible, and henceless likely to be subject to such inadvertence. If only one of thelevers 39, 40 is manually or otherwise moved to the illustrated positionwhen it should be in the toolholder supporting position, the other leverwill hold the toolholder 19 by itself.

In the event that the user should desire a safety mechanism to precludeagainst such inadvertence, we have provided an optional resilientlybiased pin 48 illustrated in FIG. 1 in a retracted position. The pin 48has a laterally projecting cam portion 49 having a ramp 50, the camportion 49 being disposed beneath a generally horizontal portion of theabutment 12 and normally urged against it by a spring 51 which providessuch resilient bias. As the guide assembly 13 is shifted to the left asexplained, the ramp 50 enables the pin 48 to rise and to move into aposition adjacent the levers 39, 40 after they have entered the groove22, making it impossible to grasp the ears 46 and to draw them togetherby an amount suflicient to release the knife-edge portions 43 from thegroove 22. On movement of the guide assembly 13 to the right aspreviously explained, the ramp 50 engages the abutment 12 to retract thepin 48 prior to the time that the abutment 12 reactively cams levers 39,40 out of the groove 22.

As the levers 39, 40 are of substantially the same thickness and aresupported on the same surface, the cam portions 44, together with theears 47 and 46 are oppositely cut away as best seen in FIG. 1 to enablethe overlap illustrated in FIG. 2. As the guide assembly 13 isabsolutely fixed during punching, the heads of the screws 34 arelikewise also fixed, whereas the stripping mechanism 16 movesdownwardly. To preclude interference between the levers 39, 40 and therearward lifter spring screws 34 during punching, suitable cutouts areprovided as shown in FIG. 2 to provide clearance.

Although various minor modifications might be suggested by those versedin the art, it should be understood that we wish to embody within thescope of the patent warranted hereon all such embodiments as reasonablyand properly come within the scope of our contribution to the art.

We claim as our invention:

1. A tool support structure for a press having a ram, comprising:

(a) a guide assembly arranged to be releasably fixedly secured to astationary portion of the press and having a first aperture;

(b) stripping means reciprocably supported in said first aperture andhaving a second aperture concentric with said first aperture;

(c) a toolholder disposed in said second aperture and normallyreleasably supported by the ram and reciprocated by said ram; and

(d) means movably carried by said stripping means and disposed in anon-supporting relation to said toolholder whenever said toolholder isaligned with said ram, and movable to a position for. supporting saidtoolholder when said guide assembly and said toolholder are releasedfrom their supports.

2. A tool support structure according to claim 1, which includes lifterspring means acting between said guide assembly and said stripping meansand having a combined preload greater than the combined weight of saidstripping means and said supporting means for insuring verticalregistration between said supporting means and said toolholder.

3. A tool support structure according to claim 1, in which said toolholder has a downwardly facing shoulder, and in which said supportingmeans comprises a pivotable lever movable to a first position in which aportion of said lever extends beneath said shoulder and is engagedthereby and to a second position where said lever portion is spaced fromsaid toolholder.

4. A tool support structure according to claim 3, in which said leverhas a cam surface normally engaged by an abutment on the press forholding said lever in said second position, and a spring for moving saidlever to said first position in response to movement of said cam surfaceaway from the abutment as said guide assembly is released from itssupport.

5. A tool support structure according to claim 4, in which said camsurface is concave for cooperation with a convex surface on theabutment.

6. A tool support structure according to claim 3 in which said shoulderby which said toolholder is supported in convex and said lever portionis concave.

7. A tool support structure according to claim 3, in which said shoulderis defined by a continuous circum- -l'crential groove in said toolholderfor enabling said lever [0 enter and coact therewith at every angularposition of said toolholder.

8. A tool support structure according to claim 3, in which saidsupporting means comprises a second pivotable lever engageable by saidtoolholder and which is substantialy a mirror image of said first namedlever, said levers being disposed on opposite sides of the center ofsaid apertures.

,9. A tool support structure according to claim 8, in which a springconnects said levers and urges them toward said first position, and inwhich each of said levers has a cam surface normally jointly engaged byan abutment on the press for holding said levers in said secondposition.

10. A tool support structure according to claim 3 which includes aresiliently biased pin having a laterally projecting cam portion forbeing normally engaged by a generally horizontal portion of the abutment0n the press for being held there-by in a retracted position, said pinbeing movable by said spring to an extended position adjacent to saidlever in response to release of said guide assembly from its support forprecluding movement of said lever out of said first position.

11. A tool support structure according to claim 10 in which said camportion has a ramp for engaging the horizontal portion of the abutmentto move to said retracted position in response to movement of said guideassembly to its operating position.

References Cited UNITED STATES PATENTS 5/1962 Fuller 83-136 9/1966Schott et a1 83-522 U. s. 01. xa. 83-635, 69:;

